The counting of stands of pipe introduced or withdrawn from a drill casing as well as the mud pumped into or out of the drill string hole is shown and described in U.S. Pat. Nos. 3,374,341; 3,646,808; 3,729,986 and 4,110,688.
The measuring of volume and density of fluids in a drilling system is shown in U.S. Pat. No. 4,043,193.